This invention relates to a combustion chamber for an engine with multiple valves and more particularly to an improved combustion chamber configuration for an engine.
One particularly popular form of combustion chamber for an internal combustion engine uses a so-called "pent roof" configuration. With this type of combustion chamber, the head or dome of the piston has upwardly tapering side surfaces which extend generally parallel to the heads of the intake and exhaust valves which are disposed on opposite sides of the cylinder bore. It is also a practice to employ a squish area which surrounds the pent roof construction so as to increase turbulence in the combustion chamber during running. Increased turbulence promote rapid flame propagation at low speeds and loads and insures more complete combustion.
Although this combustion chamber configuration has advantages, there are also some disadvantages with the type of pent roof combustion chambers previously proposed. That is, the flow of the gases from the squish area along the inclined opposite sides of the piston head are in generally parallel directions and, hence, the flow from one side directly impinges upon the flow from the other side. This directly opposing flow tends to cause irregular patterns of air and fuel movement within the combustion chamber and undesirable running characteristics. Furthermore, when the intake and exhaust valves are in their overlapping condition, these opposing flows can cause difficulties with volumetric efficiency of the engine.
It is, therefore, a principal object of this invention to provide an improved combustion chamber configuration for an internal combustion engine.
It is a further object of this invention to provide an improved pent roof type combustion chamber for a multiple valve internal combustion engine.